The technology disclosed relates to translating between a Cartesian grid and a curved scanning path that produces varying exposure doses as the scanning head traces the curved scanning path. It can be applied to writing to or reading from a workpiece. In particular, we teach use of varying exposure dose that compensates for the time it takes for the curved scan path to transit a straight axis. This simplifies either modulation of a modulator, from which data is projected onto the workpiece, or analysis of data collected by a detector, onto which partial images of the workpiece are projected.
This design team recently has described in patent applications of rotor arm scanning system with very high throughput. The rotor arm scanner can, for instance, be used to write directly to large area masks.
The use of the rotor arm for scanning, instead of a shuttlecock with a reciprocating motion or a fixed head and a moving bed, is a radical departure from standard lithographic and imaging equipment. Use of the rotor presents very challenging data path issues, as the data is presented in a Cartesian grid that requires translation or mapping for use in a polar scanning system, in which the actual scanning path also involves linear motion of the workpiece as the scanning arm rotates.
Accordingly, many new components of a data path need to be developed. Many new problems not presented by prior lithographic technologies need to be identified and solved. Resolution of the many constituent engineering challenges has the potential of contributing to an overall system that has many times the pixel and area coverage throughput of prior, reciprocating systems.